Scintillation Observations at Medium Latitude Geomagnetically Conjugate Stations

The present investigation is concerned with scintillation observations of radio signals at 40 MHz from satellite BE‐B recorded at Adak, Alaska, and at Wellington, New Zealand. The point conjugate to Adak is approximately 1000 km west of Wellington along a constant L shell. The nigttime irregularity patches that cause scintillation have a dimension 500 km in the north‐outh direction and much larger in the east‐west direction. Therefore, Adak and Wellington are sufficiently close to being a conjugate pair to permit a meaningful correlation of scintillation study. One year's data have been studied, extending from October 1964, through October 1965. The nighttime scintillation shows a semiannual variation especially equatorward of Adak and Wellington. Cross‐correlation studies indicate that the conjugate effect is statistically significant at night, but not in daytime. There is also an indication of slight asymmetry with respect to L shells. When the time difference of observations at the two stations is reduced from 2 ½ hr to ½ hr, the correlation coefficient is increased from 0.46 to 0.56. This suggests the time variability of the phenomenon under study.